Dependence of tunnel magnetoresistance on ferromagnetic electrode materials in MgO-barrier magnetic tunnel junctions
Abstract
We investigated the relationship between the tunnel magnetoresistance (TMR) ratio and the electrode structure in MgO-barrier magnetic tunnel junctions (MTJs). The TMR ratio in an MTJ with Co 40Fe 40B 20 reference and free layers reached 355% at the post-deposition annealing temperature of Ta=400 °C. When Co 50Fe 50 or Co 90Fe 10 is used for the reference layer material, no high TMR ratio was observed. The key to have high TMR ratio is to have highly oriented (0 0 1) MgO barrier/CoFeB crystalline electrodes. The highest TMR ratio obtained so far is 450% at Ta=450 °C in a pseudo-spin-valve MTJ.
- Publication:
-
Journal of Magnetism and Magnetic Materials
- Pub Date:
- March 2007
- DOI:
- arXiv:
- arXiv:cond-mat/0608551
- Bibcode:
- 2007JMMM..310.1937I
- Keywords:
-
- 73.40.Gk;
- 73.40.Rw;
- 73.50.-h;
- 75.70.-i;
- Tunneling;
- Metal-insulator-metal structures;
- Electronic transport phenomena in thin films;
- Magnetic properties of thin films surfaces and interfaces;
- Condensed Matter - Materials Science
- E-Print:
- 6 pages, 2 figures, 1 table. to be published in J. Magn. Magn. Mater
